The present invention generally relates to a coupling assembly and to a method for accelerating a vehicle and operating a transmission utilizing the coupling assembly and more particularly, to a coupling assembly which selectively reduces vehicular inertia and/or selectively slows the speed of an engine, effective to increase the responsiveness of a vehicle and to allow the transmission to be smoothly operated.
There typically exists a certain amount of time between a depression of a vehicular accelerator pedal or member and an acceleration or movement of the vehicle, especially when the vehicle is accelerated or xe2x80x9claunchedxe2x80x9d from rest or an idle state. This lag, often referred to as xe2x80x9cacceleration lagxe2x80x9d, may be more noticeable (e.g., has a relatively large amount of time) with vehicles having an automated shift manual transmission assembly or an xe2x80x9cASMxe2x80x9d type transmission assembly which causes and/or requires an engine to have a speed of about 800 revolutions per minute in the idle state and which further requires the engine to attain a speed of about 2000 rpm before acceleration actually begins. In order to allow the relatively stable speed of about 800 rpm to be obtained, at idle, a certain amount of vehicle inertia is required (e.g., a certain amount of inertial mass is applied and/or coupled to the vehicle""s crankshaft). The amount of time required for the engine to operatively obtain the speed of 2000 rpm, from its idle speed, is therefore the xe2x80x9clag timexe2x80x9d.
Further, oftentimes a shift in gear positions of an xe2x80x9cASMxe2x80x9d type transmission assembly, especially a shift from a first lower gear to a second higher gear (e.g., an xe2x80x9cupshiftxe2x80x9d), causes an undesirable movement (e.g., a xe2x80x9cjerkingxe2x80x9d) of the vehicle which is readily perceptible and annoying to the driver, especially since such shifting xe2x80x9cautomaticallyxe2x80x9d occurs without the need for the driver to physically manipulate a typical or conventional clutch member. Such xe2x80x9cjerkingxe2x80x9d is typically caused by a torque break, within the ASM transmission assembly, which occurs after the gear shift operation is initiated and continues until the gear shift operation is completed. The duration of time that the torque break occurs during such a gear shift operation is referred to as a xe2x80x9ctorque break intervalxe2x80x9d and a relatively long torque break interval causes this undesirable xe2x80x9cjerkingxe2x80x9d.
It is desirable to provide an assembly and methods which utilize the provided assembly to improve vehicle launch (e.g., to reduce or substantially eliminate xe2x80x9clagxe2x80x9d) while concomitantly allowing the transmission to be smoothly shifted (e.g., preventing and/or substantially eliminating the undesired vehicle movement or xe2x80x9cjerkingxe2x80x9d associated with a shift in gear positions).
It is first non-limiting advantage of the present invention to provide an assembly which selectively reduces vehicular inertia, such as and without limitation the amount of inertia which is applied to a crankshaft.
It is a second non-limiting advantage of the present invention to provide an assembly which selectively reduces the speed of an engine, effective to allow a transmission to smoothly transition between a first and a second gear position.
It is a third non-limiting advantage to provide a method for reducing the lag associated with the launch of a vehicle.
According to a first aspect of the present invention, an assembly for use with a vehicle of the type having a crankshaft is provided. The assembly includes a member which may be selectively coupled to the crankshaft; and an assembly which selectively disconnects the member from the crankshaft as the vehicle is accelerated.
According to a second aspect of the present invention, a method is provided for reducing acceleration lag of a vehicle having a certain amount of inertia. The method includes the steps of reducing the certain amount of inertia as the vehicle is launched.
According to a third aspect of the present invention a method for use with a vehicle of the type having an engine which may be selectively operated at a certain speed and a transmission which may be selectively moved from a first gear position to a second gear position is provided. The method is effective to allow the transmission to smoothly move from said first gear position to said second gear position and includes the step of slowing said certain speed of said engine before said transmission is moved from said first gear position to said second gear position.
These and other features, aspects, and advantages of the present invention will become apparent from a reading of the following detailed description of the preferred embodiment of the invention and by reference to the following drawings.